Any decision on an eventual no-fly zone over Syria would have to be made by the United Nations, Turkish Prime Minister Recep Tayyip Erdogan insisted on Friday.

"With respect to no-fly zone, I would like to make one observation: this is not a decision that could be taken between the U.S. and Turkey," Erdogan told a Washington think-tank during a trip to the United States.

Turkish Prime Minister Recep Tayyip Erdogan charged Sunday that Syria was dragging his country down a "vile path" with attacks such as the twin car bombings in the town of Reyhanli, near the Syrian border, that claimed 46 lives.

"They want to drag us down a vile path," Erdogan said at a rally in Istanbul, urging Turks to be "vigilant... and level-headed in the face of each provocation aimed at drawing Turkey into the Syrian quagmire."

Damascus on Sunday denied accusations it was behind twin car bomb attacks that left at least 46 people dead in a Turkish town near the Syrian border, as Ankara arrested nine people in the probe.

Cranes were seen lifting debris from buildings destroyed by Saturday's blasts in Reyhanli, one of the main Turkish hubs for Syrian refugees and rebels.

Turkish Prime Minister Recep Tayyip Erdogan has told an American television channel he believes Syria has used chemical weapons, crossing a "red line" set out by U.S. President Barack Obama.

"It is clear the regime has used chemical weapons and missiles," Erdogan told NBC News on Thursday, without providing details on when or where they were used.

Turkish Prime Minister Recep Tayyip Erdogan on Tuesday branded Israel's air raids in Syria "unacceptable" but again called on the international community to act over killings by regime forces.

"No excuse can justify this operation," Erdogan told ruling party lawmakers after Israel's weekend strikes on military sites in the war-torn country sent regional tensions soaring.

The Turkish authorities are carrying out blood tests on Syrians who have fled the fighting at home to determine if they have been victims of chemical weapons, a medical source said Monday.

"Samples have been taken from people wounded in Syria who have been transported to Turkey," the source said on condition of anonymity, adding that the results were not yet known.

Japan and Turkey on Friday signed a long-awaited deal to build a sprawling nuclear power plant on Turkey's Black Sea coast, a milestone for the Japanese nuclear industry as it recovers from the 2011 Fukushima disaster.

Turkish Prime Minister Recep Tayyip Erdogan hailed the $22 billion contract as a "very important step" that would transform bilateral relations with Japan into a "strategic partnership."

Turkish riot police used water canon and tear gas on Wednesday in a bid to disperse hundreds of protesters who defied a Labor Day ban on demonstrations in a central part of Istanbul.

The ban was imposed to avoid trouble during renovation work taking place at the symbolic Taksim square, a traditional rallying point.

Turkish Prime Minister Recep Tayyip Erdogan on Tuesday said he would go ahead with a scheduled trip to the Gaza Strip in May despite U.S. calls to delay the visit.

"There is no question of delaying this trip," Erdogan said on Turkish television.

Turkish Prime Minister Recep Tayyip Erdogan on Sunday announced plans to visit Gaza at the end of May, possibly after a key trip to Washington which brokered a rapprochement between Turkey and Israel last month.

"God willing, we will be in Gaza at the end of May. We will embrace one another there," Erdogan said through a video link with a Turkish aid center in the tiny Palestinian territory, media reported.